Brian:

When Dennis' bearing failed, albeit much more completely than yours, we found copper debris everywhere, under all the bearings (actually embedded in them) and inside the lifters. BTW, we found it impossible to flush the oil cooler completely. Gold flecks were still visible inside after we backflushed the living daylights out of it.

The motor needs to be taken down to the last bolt and oil passage plug and thoroughly cleaned and inspected. If there is copper in the lifters, they are toast. If there is copper under any other bearings, so are they. This would be an ideal time to refresh the heads, replace the cam chain tensioner blocks and chain, consider some hot cams, etc. But everything needs to be inspected and mic'd after a THOROUGH cleaning.

Here is what Porsche recommends after a bearing failure.

 

a wise man once said! Bill is right. as that "gold "stuff was all over your filter, so, the entire engine should be cleaned. Now, how is it any thing gets up into the heads if the filter catches it all. you would think that nothing could get up in the heads. Dennis saw flecks everywhere , even in the heads?? how is this possible?

 

I think this cropped up recently in a thread about crank scrapers?

This post by Erkka:

https://rennlist.com/forums/6239507-post85.html

No pictures of the operation performed, or dimensions, but an explanation of where the change is made. More specifics would be good!

 

Yes, when we did Dennis' motor, Jim Morton observed that there is a "step" that restricts the entry to the feed to 2/6. He opened that up. He and Dennis did some flow studies as well, although I wasn't there to observe them.

 

This presumes the filter is FULL FLOW under all conditions.

 

does anyone have the full oil flow diagram.....Louie posted the flow through the pump-check valves-thermostat into the filter then into the engine.....but thats as far as it goes.... I'm guessing it goes through the block-girdle 1st then up into the heads....so if thats true..then anything picked up in the lower end would work its way up to the heads?

 

As an FYI...

1.) Oil filters are only "full flow" to the point where the pressure bypass valve opens. Given this pressure is typically under 10-ish psi, at best the oil passing through the filter element is only a resonable percentage of the sump volume for each turnover of the sump.

2.) Given how the oil flow routing works, if you find it in the filter you'll find it everywhere fed past the filter.

Sorry that there is "no free lunch" here...

 

learn something new every day! that seems kind of wrong, but i guess to have full filtering, you would need to have some pretty wide and large filter element.

mk

 

I tried to cheat and re-bearing a motor once which had eaten a bearing and NOT have the head gone through/block thoroughly cleaned. Motor lasted about an hour. Sorry to say, you should probably take it all all the way apart and have it cleaned/tanked.

The additional expense of doing it right is less than the expense of doing it twice.

Scott

 

If the bearing failure is big enough, the filter will get plugged and bypass, sending debris everywhere. If the filter doesn't get plugged up enough to bypass, the debris will stop there.

The trick is to figure out if the filter bypassed, or not. This is tough to do. Some engine builders assemble with "moly" engine lube. This alone will make the filter bypass before a new engine has run for 30 minutes....not the best idea!

The lifters can be disassembled and ultrasonically cleaned...we do it all the time. The tensioners are also easy to clean.

I'd think that if you are going to have to change the crankshaft, you might as well take the entire engine apart and start over.

 

But how about the clevitte bearing assembly lube? Okay for mains and rods?

 

I had an e46M3 BWM motor fry a set of rod bearings (famous issue with them).

The factory rebuild was to replace the entire motor, and more importantly, they pulled every inch of oil tubing, pump, filter, and hardware under the assumption that metal bits were everywhere.

 

If you use any Moly, I'd change the oil filter after the initial warm-up and check-over (20-30 minutes). If you have the need to shut the engine off and the oil cools down (this means the engine ran long enough to get the oil warm), I'd change the filter.

Moly plugs the filter, very quickly. Perhaps the best thing is to not use anything with Moly in it. If you do use it, use it sparingly.

 

Not completely correct. Certainly the oil to the heads comes from the cradle, but there is not going to be a "back flushing" from the rod bearings into the cradle passages. The debris would wash off of the rod bearings and go to the pan. There it would be picked up and sent through the oil pump and into the filter.

 

You shouldn't need moly lube assembling one of these engines. Put some oil in the crankcase and spin the oil pump with a drill (or similar) until it starts to show a little oil pressure. That way the pump is primed when you crank it up the first time.